Off-periods in Parkinson disease not responding to oral treatment

A rare clinical situation occurring in the context of Parkinson disease characterized by return or worsening of symptoms (including motor and/or non-motor symptoms) under antiparkinsonian therapy. Types of off-periods are Morning Off (experienced before the first dose of the day), Delayed On (occurring more frequently after the first dose of the day or after meals), Wearing Off (end-of-dose deterioration), Sudden Off (sudden transition from on to off), and Dose Failure.